LONDON — For the past year, Stuart Adams has been fasting twice a week. While he has lost 15 pounds, the real reason he’s depriving himself is to stave off brain disorders including schizophrenia and Alzheimer’s disease.

“There’s a virulent strain of madness running through my family, and I reckoned my chances of going down that route were pretty high,” said Adams, 43, a freelance translator and interpreter in London who learned of a possible link between Alzheimer’s and diet while watching a BBC documentary last year. “Anything that could help with that was of great interest.”

Fasting two or more days a week is catching on as people seek ways to avoid a range of ailments linked to obesity from dementia to cancer. Building on promising findings in studies of mice by the U.S. National Institute of Aging, researchers are planning the first studies in humans of fasting’s potential to stave off the onset of Alzheimer’s. That disease is just one of many in which scientists are making progress understanding how fasting may help prevent illness.

Because there is no cure for Alzheimer’s, which afflicts more than 35 million people, any possibility of prevention holds huge potential. Adams was inspired to try the diet last year after the BBC documentary called “Eat, Fast & Live Longer” cited a study in mice that suggested intermittent fasting could delay the onset of cognitive disorders.

The study was led by Mark Mattson, professor of neuroscience at Johns Hopkins University in Baltimore and senior investigator at the U.S. National Institute of Aging. Mattson is planning a new project to measure how fasting twice a week for two months affects human brain function and early signs of Alzheimer’s.

While this and other similar diets are gaining in popularity even as they spawn a steady outpouring of new books on the subject, some experts have doubts.

“This is part of a never-ending carousel of diet books,” said Kelly Brownell, former director of the Rudd Center for Food Policy and Obesity at Yale University and now dean of the Sanford School of Public Policy at Duke University. “Some people will go on it, and because they’re cutting their calories, they will be successful. There will be some buzz and then the diet will go away, never to be heard of again.”

Nonetheless, the studies and the books keep coming. Another examination into the fasting-dementia link will be led by Krista Varady, an associate professor of kinesiology and nutrition at the University of Illinois at Chicago. Her research focuses on alternating a normal diet with eating 500 or 600 calories every other day. Nutritionists recommend men consume about 2,500 calories a day and women 2,000 calories.

While research on fasting diets and dementia still has a long way to go, the early evidence is promising. The mouse study led by Mattson found that intermittent fasting may have protected the function of brain cells, even if it didn’t reduce levels of the plaque and tangles that are typical signs of Alzheimer’s. Mattson’s earlier study suggested that fasting increased production of a protein called brain-derived neurotrophic factor, or BDNF, which enhances learning and memory.

At the same time, fasting is increasingly seen as playing a role in the prevention of other diseases including breast cancer and diabetes. That’s paved the way for a flurry of how-to books including Varady’s “The Every-Other-Day Diet,” which goes on sale Dec. 24. Competing with that is “The Fast Diet” by science journalist Michael Mosley, who was behind the BBC documentary Adams watched, and lifestyle writer Mimi Spencer. Their regimen is known as the 5:2 diet.

There’s also “The 2-Day Diet” by dietitian Michelle Harvie and Tony Howell, a professor of oncology at the University of Manchester in England. Their approach was developed specifically to help prevent breast cancer, for which obesity is a known risk factor.

“In general, intermittent fasting is a good thing if it’s done properly,” said Dean Ornish, a professor of medicine at the University of California at San Francisco and a physician consultant to former President Bill Clinton. “But if you’re already eating very healthily, then you may not need to do that.”

Unlike Mosley’s 5:2 diet and other copycats, where “no foods are off-limits” on the non-fasting days, Harvie and Howell’s “2-Day Diet” calls for a Mediterranean diet for five days and two consecutive days of eating from 600 to 1,000 calories and no more than 40 grams of carbohydrates.

In a study conducted with Mattson and published this year, they found the two-day diet led to greater drops in body fat and insulin resistance in women with high breast-cancer risk after three months, compared with a diet where calories are cut every day, suggesting that intermittent fasting is an easier approach to follow.

Howell is also analyzing results from a study looking at how the diet switches some breast genes on or off in women with high cancer risk.

The bottom line, though, is that any fasting diet needs to be undertaken thoughtfully, including eating healthy foods on non-fasting days, Harvie said. She also believes more research is needed on fasting’s long-term benefits and sustainability.

“The science definitely needs to catch up with the hype,” she said in an interview in Manchester. “There is something there, but we need to get it right.”

Seeking ways to avoid a range of illnesses that stem from obesity — such as Alzheimer’s and cancer — many people are turning to fasting. While the research is still new, the concept and the hype is growing.

Hi USA good to see you are still around. Your post has some relevance to me as in my retirement years I drive an ambulance taking Dementia and Alzheimer sufferers to and from hospital for treatment. I see the slow, creeping effects these insidious diseases have on unlucky sufferers.
I did a little research and discovered that India has among the least numbers of sufferers in the developed world. It is thought that Tumeric may be a significant factor as this spice is used a lot in Indian cooking. It is also believed to have some identifiable properties that may help combat these diseases but as is the case more needs to be done. I myself am trying to take a small daily amount in a broccoli and water smoothy but find it is a difficult taste to become accustomed to. Keep the info coming and good luck with your diet.

Hi piper, thank you for your suggestion to try mustard in place of turmeric. I know turmeric is an ingredient in some mustards, (it gives it the yellow colour) but I am not much of a fan of mustard. Your reply did make me think about adjusting the amount of turmeric in my concoction and a smaller amount seems to work for me. So thank you.
Just a bit of useless information (I am good at that). Michael Caine, one of our great actors and the reason for the Batman film successes!!! says he takes a small amount of turmeric daily and at dinner has a single small glass of red wine. The reason re the wine is so he can have another glass the next day…… not a lot of people know that.
Good luck.

Have only just gotten to this post. An interesting article, USA. And the reason I am doing the fasting as my husband has early onset dementia. Scary and unpleasant.

Couscous, thanks for the reply you gave me re the turmeric a week or so back. I am new to posting and responded by email Duh!!! Anyway I have been aware of the turmeric theory and take it with lemon juice and water – when I remember. Tee Hee. Perhaps I really do need this fasting business.

Absolutely. Unfortunately the evidence, if those in care where my husband is are any example, appears to show dementia has no respect for intellect. There are physicians, chemists, dentists, academics there. All of whom were mentally stimulated. I think what is so interesting is the new science which seems to link insulin resistance, the consumption of fats and the influence of calorie consumption to this ghastly disease.

Good on you for using all those apps. I can’t remember what it was like before we had all these great gadgets.

You will definitely be getting the distinct impression that I am thick but please where do I do a profile? Just in the threads? There are a number of people I have been reading who it would interesting to know a bit more about. At the top of the site it tells us to introduce ourselves but when you click on it your find yourself at the list of forums. I enjoy those with a sense of humour. Oh Lord, don’t you need one some days?

Hi Couscous (and others interested in the effects of turmeric) – I have been told by a pathologist that India also has the lowest rate of gastric cancer in the world and that one of the reasons for this is the daily intake of turmeric in their food. Apparently it lowers the rate of inflammation which causes numerous diseases. Although my husband is Indian, we don’t like to eat curries every day, so I found a small gadget online that allows you to fill your own capsules which I load with turmeric (available very cheaply in Indian grocery stores). I take two capsules in the morning and two at night. Turmeric capsules are sold in health food shops, but the price is ridiculous … making your own is just so easy and only a tiny fraction of the cost. The website is http://www.CapsuleConnection.com – I might add that I am recommending this as a satisfied customer and have no other link to this company. 🙂

Hi caros. Thank you for the information and research about the capsule gadget. I intend buying one. As I have said in previous posts I believe in the medical research concerning Turmeric. However the taste of it in powder form as an addition to the Broccoli shake I have daily is an aquired taste. I have also passed on your comments to family members who may find it helpful.
Good luck.

I’ve been doing the 5:2 for half a year now. It was always about losing weight for me, yet I knew about the repairing cells bit, for example with helping with dementia. Now I eat a lot of sugar, and it is rotting my brain. I always knew this, because my memory is atrocious.

I found though, every following day after I fasted, i felt like my mind was sharpened up! I’d start remembering things I’d not even considered remembering before, and constantly surprised myself.

My worry now, is this: I obviously have a target weight goal. Once I meet that goal, I’ll stop fasting and lose the benefits I’m getting with my memory.
I have tried the method of not eating for 24 hours instead of 5:2, but I could only make it till the early afternoon.

On a side note, I’m wondering if my eyesight is better through fasting? Over the past 6-8 years, my eyes have been getting really bad, dropping each time enough to give the optician a worried tone to their voice. Since fasting, it has felt like my eyes are sharpening up! Could all be in my head of course 🙂 I’ll update this feed on my next eye test.